Crane bridge



Aug. 29, 1961 W. S. CHAPIN ET AL CRANE BRIDGE 2 Sheecs-Sheekl l Filed Dec. 8, 1958 Aug. 29, 1961 Filed Dec. 8, 1958 W. S. CHAPIN ET AL CRANE BRIDGE 2 Sheets-Sheet 2 Jersey Filed Dec. 8, 1958, Ser. No. 778,748 7 Claims. (Cl. 10S- 163) The present invention relates generally to overhead traveling cranes and concerns more particularly, bridges for use in such traveling cranes.

An overhead traveling crane installation usually includes a pair of parallel runway beams which dene a track along which a crane bridge may travel. The crane bridge is suspended on the track and provides a laterally extending trackway between the runway beams along which the lifting mechanism may ride. The bridge thus carries the lifting mechanism along the runway beams While allowing the mechanism to shift laterally between the beams by riding on the bridge. y In actual practice, almost every crane installation is somewhat different. The spacing of the runway beams, the shape of the beams, the capacity of the crane, and Whether or not the bridge is hand or power driven, are all matters of user preference which makes construction of each crane bridge a distinctive problem.

It is therefore an important object of the invention to provide a novel crane bridge structure made up of standard assemblies and parts which can be produced in quantity to be carried in stock, and which form bridges ofrwidely varying capacity and adaptability. With more particularity, it is an object to provide a bridge as characterized above which can be easily utilized with runway beams of various sizes and forms so that the user may use beams of available or desired types for the runway track of the crane.

It is also. an object to provide a novel bridge of the above type which is economical to construct since it employs fewer components than conventional units. It is a related object to provide -a bridge of this character which is exceptionally well suited for heavy duty operation Vwith low maintenance costs.

In more detail it is an object to provide a bridge as described above which can be modified for hand or power operation easily, conveniently, and economically.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIGURE 1 is a plan View of a crane bridge constructed in accordance with the present invention and riding on runway beams shown sectioned and partially broken away;

FIG. 2 is a fragmentary section taken along the line 2--2 in FIG. 1;

FIG. 3 is a section taken along the line 3--3 of FIG. 1; and

FIG. 4 is a fragmentary plan view of a modified driving mechanism for the bridge shown in FIG. 1.

While the invention will be described in connection With a preferred embodiment, it will be understood that ,we do not intend to limit the invention to that embodiment. On the contrary, we intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by rthe appended claims.

'Iurning first to FIG. 1, there is shown a crane bridge 15 riding on a track made up of parallel runway beams 16 and 17. The beams 16, 17 preferably have a standard the cross girder 18 is a wide flange I-beam (see FIG. 3)

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and is provided `with capping in the form of a pair of angles 21, 22 secured to the top flange of the girder.

A bridge drive shaft 25 is journaled on the girder 18 and extends between the two end trucks 19 and 20. In the illustrated embodiment, the drive shaft 25 is supported by journal blocks 26 carried at the outer end of arms 27 which are bolted to the cross girder through interposed spacers 28 (see FIG. 3).

Turning with more particularity to the end trucks 19, 20, each truck includes a frame made up of a pair of parallel members 31, 32, preferably in the form of outwardly facing channels, which are connected at their opposite ends by U-shaped plates 33, 34. The center or cross portions 33a, 34a of the U-shaped plates 33, 34 respectively, lie well beneath the bottom flanges of the trackway -beams 16, 17 (see FIG. 2) so that the trucks 19, 20 may move freely along the beams.

Each of the end trucks 19, 20 are provided with a pair of opposed support wheels 41, 42 and a pair of opposed drive wheels 43, 44, which ride on the upper surfaces 45, 46 of the lower flange of the runway beams 16, 17. It may thus be seen that the bridge 15 is of the underhung type with the cross girder 18 being suspended beneath the runway beams 16, 17.

As a feature of the invention, the frame members 31, 32 of the end trucks have mounting pads 51 secured thereto and interposed between the frame members and the cross girder 18. In this way, assembly of the crane bridge 15 is facilitated in the field since the pads 51 can either be welded about their periphery to the cross girder, or bolts can be passed through the pads and the girder, whichever assembly method is most convenient.

In carrying out the invention, the end portions of the drive shaft 25 are formed with gear teeth which are in meshing engagement with gear teeth cut in large iianges formed as part of the drive wheels 43, 44. In the illustrated embodiment, the end portions of the drive shaft 25 are formed as separate pinion shafts 52 which are coupled to the drive shaft 25 by means of pinned sleeves 53 (see FIG. 2) `and are provided with Agear teeth 60. The drive wheels 43, 44 are formed with integral rim portions 54, 55, respectively, and flange portions 56 and 57, respectively. The ange portions 56, 57 are of a substantially greater diameter than the portions 54, 55 and the outer periphery of the flange portions are formed with gear teeth 58, 59, respectively, which are in meshing engagement with the gear teeth 60 cut into the pinion shafts 52.

lBecause of the considerable speed reduction atforded -by the relatively small pitch diameter of the gear teeth 60 on the pinion shafts and the much larger pitch diameter of the gears formed on the drive wheel flanges 56, 57, it will be yappreciated that the shaft 25 and its pinion shaft extensions 52 operate under low torque forces in transmitting power to the drive Wheels. The shaft and its extensions may therefore be of an economical, convenient size and in actual practice it has been found that a 1%; inch diameter drive shaft can be used to drive crane bridges having capacities of 4from 1A ton to 10 tons. It will also be appreciated that by forming driving gear teeth in extensions of the drive shaft 25 the necessity for providing sets of relatively expensive pinion gears at each end of the drive shaft is eliminated.

In keeping with the invention, both the pinion shafts 52 forming the ends of the drive shaft 25 and the drive wheels 43, 44 of each end truck are mounted in common pillow blocks secured to the frames of the drive trucks so that the gear teeth on the respective drive wheels and pinion shafts are positively held in proper meshing engagement. In the preferred construction, pillow blocks 61 are secured in opposed relation to the inner surfaces of the end truck frame members 3'1, `32 and each block is mounted portions 62 extending beyond the respective frame members 31, 32. Bearings 63v are mounted in the extending .portions `62 which support the pinion shafts 52 so that these shafts pass under the truck frame memf bers. For mounting the drive Wheels 43, 44, the wheels are journaled on pins 65 `by, suitable bearings 66 and the pins are tted through -alined apertures 67 and 68 in the pillow block `61 :and frame members respectively. It can thus be seen that assembly of the end trucks 19, 20 is facilitated since the drive wheels 43, 44 and the pinion shafts 52 which have meshing gear portions, are supported in common pillow blocks I61 sothat exact alinement of the meshing gear teeth is easily obtained. This also results in reliable operation and low maintenance costs as proper meshing engagement between the gear teeth 5S, 59V of the drive wheels and the gear teeth 58, 59 of the drive wheels and the gear Vteeth 6i) of the pinion shafts 5-2 is determined and maintained by the relatively massive pillow blocks 61.

Pursuant to the invention, the pins 65 supporting the drive wheels 43, 44 areV adjustably mounted and the gear teeth 60 of the pinion shafts are spline-like and extend axially of the pinion shafts between the pillow blocks 61. In this way the drive wheels may be adjusted toward and away from one another while remaining in positive, predetermined Vmeshing engagement with the respective pinion shafts.

In order toradjustably secure the'pins 65,V the pins are provided with end caps 70 on their outer ends which are |bolted to the respective frame members 31, 32 with a number of washers or shims 71 inter'posed between the end caps and the outer surface of the frame member. It will be gappreciatedthat Yby varying the number offshims 71, the spacing of the drive wheels 43, 44 betweenthe truclc frame members 31, 32 can be varied.

For the purpose of mounting-the supporting/wheels 41, `42 on each of the end trucks 19 and 20, thesewheels are journaled on pins 65a which are fitted into pillow fblocks `61a in a mann-er identical to` that in which the drive wheels 43,44'are mounted and as described above' (see FIG, 1). Thus, the supporting wheels 41, 42 can also be Sadjustably positioned within the end truck frame in the same manner as the drive wheels 43, 44. f

The rim portions 54, 55 ofthe drive wheels 43, 44 and the corresponding rim portions of the supporting wheels 41, 42 yare Vprovided with peripheral portions having rounded cross sections (see FIG. 2) so as toadaptthe wheels for riding on surfaces having varying slopes. That is, the upper flange surface 46 of the runway beam 16 (see PIG. 2) may vary in, slope between the 4relatively wide limits indicated by the dashed lines 46arand-46b without adversely affecting the smooth rolling vcontact of the wheel rims lonthe runway beam flange. Y

It may now be seen that theend trucks 19, 2li are easily adaptable for use with a wide variety of runway beams having different sizes and shapes. When a narrow flangeV beam is encountered, the supporting drive wheels are simply, adjusted by removing the required number of ,shims 71. Because of thespline-like gears ,60 onthe drive shaft extensions 52 the drive wheels 43, 44're`rnain in propermeshingengagement with the drive shaft in all their relative positions of. adjustment.. The Vrounded pe- .ripheries of the' wheel rims Vare Yautomatically suited to Vride easilyV on surfaces having varying slopes.

Considering FIG. 4,- it can be seen that the bridge 15 is easily adaptable for either. hand or power. operation. In the modification shown in FIG.y l, a pulley 8d adapted toj be rotated by a hand pulled chainV isshown secured to the drive shaft 25. In Vthe modification shown in FIG; 4 wherein elements correspondingY to those previously `described have'be'en given corresponding numbersV with the distinguishing suiiix a' added, a irrotor'd` is'shown 'su'pported vby aplatform 82 thisis Vsuspended betweenV arms i27a. The motor drive shaft'83 is directly-coupled at vv'each of its 'ends' vto rthe drive shaft ZSa'which Yhas. been l 4 split to receive the motor. Direct drive between the motor drive shaft 83 and the bridge drive shaft 25a is possible because of the substantial speed reduction afforded between the drive shaft end portions and the respective drive wheels'. YNo gear reduction transmission is required between the motor and -the bridge drive shaft. Y Because of the low'torque forces carried by the bridge drive shaft 25a, the saine shaft can be utilized for both hand and power operation of the bridge. Those skilled in the art will thus, appreciate that conversionof the bridge 15 from hand to motoroperation is unusually simple.

We Claim as our invention:

1. In a crane bridge for an overhead traveling crane, a truck assembly comprising, in combination, a frame including a pair of parallel members, a pinion shaft carried by said frame and extending between said members, a pair of drive wheels each being journaled on a respective one of a pair of pins, said pins being tted in respective ones of said members so 4as to support Said wheels in opposed relation, means -for adjusting said drive wheels toward and away from one another, said pinion shaft having spline-like gear teeth formed thereon extending between said members, said drive wheels having gear portions in meshing engagement with the gear teeth on said shaft so that rotation of the shaft will power the wheels in all of their positions of adjustment.

2. In a crane bridge for an overhead traveling crane, a truck -assembly comprising, in combination, a heme member, a pillow block secured to said member Aand having a portion extending beyond said member, a pinion shaft journaled in said extending portion, adrive wheel journaled on a pin, said pin 'being adjustably fitted in said block so as to support said Wheel, said drive wheel having a rim whose periphery has a rounded cross section so as to adapt the wheel for riding on surfaces having varying slopes, said pinion shaft having splinelike gear teeth formed thereon, said drive Wheel having a gear portion in meshing engagement with the gear teeth on said shaft so that rotation of the shaft will power the wheel in all of its positions of adjustment.

3. In a crane bridge `for an overhead traveling crane, a truck assembly comprising, in combination, a-frame including a pair of parallel members, a pair of pillow blocks each secured -to a respective one of said members, a pinion shaft journaled in and extending between, Said blocks, Va pair of drive wheels each being journaled'on a respective one of a pair of pins, said pins being adjustably iitted in respective ones of said blocks so as to support said wheels in opposed relation, said pinion shaft having spline-like gear teeth formed thereon extending between said blocks, said drive wheels having gear portions in meshing engagementwith the gear teeth on said shaft so that rotation of the shaft will power the wheels in all of their positions of adjustment.

4. In a crane bridge forran overhead traveling crane, a truck assembly comprising, in combination, a frame including a pair of parallel members, a pair of pillow blocks each secured to a respective one of said members, said blocks having portions extending beyond theirv respective members, a pinion shaft journaled in said extending portions between said blocks, a pair of drivewheels each being journaled ona respective one of said blocks soas Yto support said wheels in` opposed relation, and said `drive wheels having gear portionsin meshing engagement with gear teeth on said'shaft. Y .Y j

5. In a crane bridge for an overhead traveling crane, a truck assembly comprising, inY combination, a frame including a pair of parallel members, a pair of pillbw blocks each secured toa respective one of said members, said blocks having 'portions extending beyond their respective members, a pinion shaft iournaled in said extending portions between said blocks, a'pair of drive wheels each being journaled on a respective one of a pair o'fpins', said pins being adjustably tted in respective ones of said blocks so as to support said wheels in opposed relation, said drive wheels having opposed peripheries with rounded cross sections so as to adapt the wheels for riding on surfaces having varying slopes, said pinion shaft having spline-like gear teeth formed thereon extending between said blocks, said drive wheels having gear portions in meshing engagement with the gear teeth on said shaft so that rotation of the shaft will power the wheels in all of their positions 'of adjustment.

6. In a truck assembly for the crane bridge of an overhead crane, a drive wheel assembly comprising, in combination, a frame member, a pillow block secured on said frame member, a pin fitted in an aperture through said frame member and said pillow block, means for securing said pin in said aperture, a drive wheel journaled on said pin adjacent said block, said Iblock having a portion extending beyond said frame member, a drive shaft journaled in said extending portion, and said drive wheel and said drive shaft having gear teeth held in proper meshing engagement bythe common mounting of the pin and the shaft in said pillow block.

7. In a truck assembly for the crane bridge of an overhead erane, a drive wheel assembly comprising, in cornbination, a frame, a pin fitted snugly through an laperture formed in said frame, a drive wheel journaled on one end of said pin adjacent said frame, a drive shaft journaled in said frame, said drive `shaft and drive Wheel ha'ving gear teeth in meshing engagement, an end cap secured to the end of said pin opposite the pin end carrying said drive wheel, and means `for releasably securing said end cap at varying distances from said frame so as -to adjustably position said drive Wheel.

References Cited in the le of this patent UNITED STATES PATENTS Nyblom Nov. 25, 1958 

